In This study, the extraction trend of thorium(IV) has been investigated by tri_butyl phosphate(TBP) in kerosene in a pulsed disc and doughnut extraction column. The effects of operational variables such as pulsation intensity and dispersed and continuous phase flow rates on dispersed phase holdup, satuer-mean drop diameter and overall volume mass transfer coefficients have been investigated and found to be significant. The existence of three different operational regimes, namely mixer-settler, dispersion and emulsion regimes was observed when the energy input was changed. As expected, smaller mean drop sizes between 1.1-2.8(mm) are obtained with the increase of pulsation intensity. The results also show no significant effect of continuous phase flow rate on mean drop size, which increases to 35% with increase of dispersed phase flow rate for the oprating conditions investigated. The results indicated that the characteristic velocity approach is applicable to this type of extraction column for analysis of dispersed phase holdup in the transition and emulsion regions. The results show that the column performance increases with an increase in pulsation intensity. At high pulsation intensity, however, the overall volumetric mass transfer coefficient decreases due to the production of very fine dispersed droplets. It was also found that the column performance decreases with both an increase in dispersed phase velocity and a decrease in continuous phase velocity. An empirical correlation for prediction of the continuous phase overall mass transfer coefficient is derived in terms of the overall Sherwood number,Reynolds number and dispersed phase holdup for continuous phase? dispersed phase mass transfer direction. The prediction of continuous phase overall mass transfer coefficient from the presented correlation is in good agreement(error:13%) with experimental data. Keywords : Thorium, Pulsed disc and doughnut column, Dispersed phase holdup, Sauter-mean drop diameter, Mass transfer coefficient